The Senate prides itself on being the world’s greatest deliberative body, but that doesn’t mean one can say just anything. In fact, if you say something out of bounds, a colleague can invoke a rule that forces you to sit down and be quiet.

This dynamic came into focus over the weekend. As shutdown tensions ran high, Rule 19 was pulled out for a fresh reading as a reminder about the chamber’s standards for decorum.

On Sunday, Sen. Sherrod Brown made comments on the floor about who wrote the continuing resolution that passed Monday, as well as the tax overhaul law that was signed into law in December.

“We know how this bill’s been written down the hall about 100 feet, in Sen. McConnell, the majority leader’s office. The bill was written by Wall Street lobbyists,” Brown said, referring to Republican leader Mitch McConnell. “The tax bill was written in Sen. McConnell’s office by a bunch of tax lawyers.”

The Ohio Democrat also took issue with the 49 members of the Democratic caucus, who “represent more than half the population of this country,” not being included in discussions on the spending bill.

That prompted Republican Sen. Thom Tillis of North Carolina to interrupt Brown and call for a rule refresher. The Senate’s presiding officer, Sen. John Barrasso, then read portions of Rule 19, which governs speech and debate.

“If any Senator, in speaking or otherwise, in the opinion of the Presiding Officer transgress the rules of the Senate the Presiding Officer shall . . . call him to order,” the Wyoming Republican read. He continued that “when a Senator shall be called to order he shall take his seat.”

That is the same rule used to prevent Massachusetts Sen. Elizabeth Warren from speaking during last year’s consideration of former Sen. Jeff Sessions’ nomination to be the attorney general. She was reading statements from a 1986 letter by the late Coretta Scott King in opposition to Sessions’ nomination at the time to the federal district court.

Brown was not forced to sit down, and he seemed confused about why exactly Tillis thought he had said something out of turn.

“Does that mean what I said, that Sen. McConnell didn’t have lobbyists in his office writing legislation, is that what Rule 19 means and what the presiding officer is now discussing with the parliamentarian or my friend from North Carolina is alleging?” Brown asked.

Barasso replied, “The chair is merely reminding all senators of the rule.”

To which Brown replied,“I’m not impugning anybody’s motive. I’m just stating what I read in newspapers and what seems to be fact.”

So, no harm, no foul.

Regardless, with the coming slate of high-profile and contentious legislation coming down the pike, one might expect more senators to invoke Rule 19.